Possible role for carbamyl phosphate in the control of liver glycogen synthesis

Isotopic data suggested a possible correlation between the activation of liver glycogen synthesis and some unstable intermediate. Carbamyl phosphate was one candidate considered. L-Norvaline, an inhibitor of ornithine transcarbamylase, is known to increase intracellular carbamyl phosphate levels. L-Norvaline augmented the increase in glycogen synthesis caused by L-glutamine and L-alanine, and also induced considerable glycogen synthesis with ammonia as the nitrogen source.